NASA is seeking proposals for science instruments to fly on a lander that will touch down on the surface of a comet as part of a mission to be launched in 2003.

The space agency has released an announcement of opportunity for Champollion, a U.S.-French lander that would be flown as part of the European Space Agency's Rosetta orbiter mission.

Plans call for Champollion to carry about six instruments, including such experiments as spectrometers to study the makeup of the comet nucleus, gas and thermal analyzers, an imager/microscope, temperature sensors, an accelerometer and a radio sounder.

Launched on an Ariane 5 rocket from French Guiana, Rosetta will fly by Mars once and Earth twice before its rendezvous with Comet Wirtanen in 2011. Cameras on the orbiter will be used to select the landing site for Champollion, which will descend to the comet's surface in 2012. Champollion will be powered by batteries, limiting its science-gathering mission to 84 hours on the surface of the comet.

Maximizing the science return on investment is a major goal for the project. In addition to achieving savings by flying the comet lander mission with a European Space Agency comet rendezvous mission, Champollion will draw on new technologies in microminiaturized sensors to fly as many science instruments as possible within a total lander weight of only 50 kilograms (110 pounds).

Plans call for NASA to build the lander, with the French space agency, Centre National d'Etudes Spatiales (CNES), providing the interface to the Rosetta spacecraft, some subsystems on the lander and major portions of the ground operations system. CNES is simultaneously issuing its own announcement of opportunity for Champollion; selection of instruments for the lander will be carried out jointly by NASA and CNES.

The mission is named for Jean Francois Champollion, the French scholar who deciphered the Rosetta Stone. Discovered in Egypt in 1799, the artifact contained inscriptions in several languages that supplied the key to understanding Egyptian hieroglyphics. Modern-day scientists believe that comets, which preserve material from the ancient solar system, may similarly help them solve questions of how planets developed and life began on Earth.

An information package for teams preparing proposals is available on Internet via the World Wide Web system at the address http://champwww.jpl.nasa.gov/champollion/ao.html. Printed copies are available from the Solar System Exploration Division, Code SL, NASA Headquarters, Washington DC 20054.

Notices of intent must be filed with NASA Headquarters by March 31, with final proposals due by June 2. The agency expects to make provisional selection of science instruments in October.

NASA's Jet Propulsion Laboratory, Pasadena, CA, is managing the study of the U.S. portion of the Champollion mission for NASA's Office of Space Science, Washington, D.C.